Morphological Characterization of Nicotiana tabacum Inflorescences and Chemical-Functional Analysis of Extracts Obtained from Its Powder by Using Green Solvents (NaDESs)

LEAL, MARIANA; MORENO, MARÍA ALEJANDRA; ALBORNOZ, PATRICIA LILIANA; MERCADO, MARÍA INÉS; ZAMPINI, IRIS CATIANA; ISLA, MARÍA INÉS

Plants

MDPI

Año: 2023 vol. 12

The production of smokeable tobacco for use in cigarettes is characterized by the productionof pre-harvest and post-harvest waste, with ensuing undesirable effects on the environment. Theinflorescences of tobacco after blunting, deflowering, or topping are considered pre-harvest wasteand left in the field. Using green and ecofriendly solvents such as Natural deep eutectic solvents(NaDESs), these wastes could be used to obtain antioxidant molecules of interest in cosmetics.Taking into account its potential as plant matrix to obtain metabolites of commercial interest, tobaccoinflorescences and inflorescence powders of different particle sizes were characterized by optic andelectronic microscopy. Thus, the powdered inflorescences were extracted with four conventionalsolvents, i.e., distilled water (DW), acetone: distilled water (AW), ethanol 70◦(EW), methanol (Me),and five NaDESs, i.e., lactic acid: sucrose (LAS), lactic acid: sucrose: distilled water (SALA), fructose:glucose: sucrose: distilled water (FGS), choline chloride: urea: distilled water (CU), and citric acid:propylene glycol (CAP). Among the tested NADESs, SALA was the most promising solvent; higherextraction yields of total phenolic compound (3420.0 ± 9.4 µg GAE/mL) than conventional solventswere attained and it was the only selective solvent to phenolics. CU was the best solvent for flavonoids and alkaloids extraction (215.3 ± 3.2 µg QE/mL and 392.3 ± 8.0 µg ACE/mL, respectively). All extracts showed antioxidant activity. A heatmap with dendrogram and main component analysis showed that acid-based NaDESs are grouped together, this group being the one with the best performance in H2O2 scavenging. The extracts obtained with green solvents could be used directly in cosmetic formulations as antioxidant ingredients because both tobacco flower oil and flower extracts are listed in the cosmetic ingredients database as non-toxic products. Additionally, the demand for sustainable ecological cosmetics is growing. In this sense, NaDESs represent an opportunity to develop innovative extracts with unique phytochemical fingerprints and biological activities.